
//

// sender.cpp
// ~~~~~~~~~~
//
// Copyright (c) 2003-2012 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include <boost/asio.hpp>
#include "boost/bind.hpp"

#include <iostream>
#include <sstream>


const short multicast_port = 30001;
const int max_message_count = 10;

class sender {
public:
    sender(boost::asio::io_service &io_service,
           const boost::asio::ip::address &multicast_address)
            : endpoint_(multicast_address, multicast_port),
              socket_(io_service, endpoint_.protocol()),
              timer_(io_service),
              message_count_(0) {
        std::ostringstream os;
        os << "Message " << message_count_++;
        message_ = os.str();
        socket_.async_send_to(
                boost::asio::buffer(message_), endpoint_,
                boost::bind(&sender::handle_send_to, this,
                            boost::asio::placeholders::error));
    }

    void handle_send_to(const boost::system::error_code &error) {
        //发送max_message_count条信息,信息发送完成后io_service事件循环完成;服务端退出
        //由于时udp通信,所以没有保证是否有客服端收到
        if (!error && message_count_ < max_message_count) {
            //重置timer_定时1s后调用 boost::bind(&sender::handle_timeout, this,boost::asio::placeholders::error)
            timer_.expires_from_now(boost::posix_time::seconds(1));
            timer_.async_wait(
                    boost::bind(&sender::handle_timeout, this,
                                boost::asio::placeholders::error));
        }
    }

    void handle_timeout(const boost::system::error_code &error) {
        if (!error) {
            std::ostringstream os;
            os << "Message " << message_count_++;
            message_ = os.str();
            socket_.async_send_to(
                    boost::asio::buffer(message_), endpoint_,
                    boost::bind(&sender::handle_send_to, this,
                                boost::asio::placeholders::error));
        }
    }

private:
    boost::asio::ip::udp::endpoint endpoint_;
    boost::asio::ip::udp::socket socket_;
    boost::asio::deadline_timer timer_;
    int message_count_;
    std::string message_;
};

int main(int argc, char *argv[]) {
    try {
        if (argc != 2) {
            std::cerr << "Usage: sender <multicast_address>\n";
            std::cerr << "    sender 239.255.0.1\n";
            std::cerr << "  For IPv6, try:\n";
            std::cerr << "    sender ff31::8000:1234\n";
            return 1;
        }
        boost::asio::io_service io_service;
        sender s(io_service, boost::asio::ip::address::from_string(argv[1]));
        io_service.run();
    }
    catch (std::exception &e) {
        std::cerr << "Exception: " << e.what() << "\n";
    }
    return 0;
}
